Mining machine



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e sheets-sneey-'l mil INVENTORJ Einar M. Arentzen BY Harry Jack Filied Marl'i 2. 1959 June 22, 1965 E. M. ARENTZEN ETAL MINING MACHINE 6 Sheets-Sheet 2 Filed March 2,.4 1959 E. M. ARENTZEN ETAL.

June 22, 1965 MINING MACHINE 6 Sheets-Sheet 5 Filed March 2, 1959 mmJ N. n Xu l wml! -I 4| Il! June 22, 1 965 E. M. ARENTZEN ETAL 3,190,698

MINING MACHIN Filed Maron 2, 1959 e sheets-sheet 4 Figf.

June 22 1955 E. M. ARENTZEN ETAL 3,190,698

MININGV MAcHINE `Filed March 2 1959 6 Sheets-Sheet 5 co l0 INVENToRs f Einar M.Aren1zen BY Harry Jack M,M r ma( '1mm-THU ,2. Awww lli. EL fm E. M. ARENTZEN ETAL 3,190,698

June 22, 1965 MINING MACHINE '6 Sheets-heet 6 Filed March 2- 1959 I wm Il -lm .mVV mmv. `N\ NN www mw i// t mmf@ m ,-fwo mv .5. m Nw w) www w Nw mm W". Il.' Ow w w mm mm H n M 1M! o G G G Nm .vn mh wm mm mm v:

United States Patent() 3,190,698 n, i MINING MACHINE Einar M. Arentzen, Charleroi, and Harry Jack, North Charleroi Borough, Pa., assignors, by mesne assignments, to Lee-Norse Company, Charleroi, Pa., a corporation of Delaware Filed Mar. 2, 1959, Ser. No. 796,455 3 Claims. (Cl. 299-64) lrange between twenty-eight and perhaps forty inches in thickness. The mining of s uch coal, because of space limitations, is economical only if the coal can be removed .mechanically, and the present invention has for its principal object to provide a practical compact mining machine of low vertical height capable of mining the coal and carrying it away from the working face to be loaded into cars or other conveying means-effectively, rapidly, and with a minimum amount of hand labor.

More specific important objects of our invention are to provide a mining machine for use in low seams which has a unique cutting and gathering means that will operate to cut a relatively wide span at the working face, much wider than the minimum overall width of the machine to allow adequate space for the machine operation; that will leave little coal for hand removal, and operate effectively to remove a large amount of coal with each increment of forward penetration into the mine. v

A further important object of the invention is to provide a machine which is highly maneuverable, adaptable `to coal seams of different thickness, and capable of adapting itself to irregularities in the contour of the floor or roof or to dip or slope in the seam.

A further important object of our invention is to pro- Vide a gathering mechanism that will move the coal as itis cut away at the working face and force it onto a conveyor that carries the coal rearwardly from the forward end of the machine.

Further objects are to provide a low coal mining machine of rugged, safe construction which can stand the abusive treatment to which equipment in such environment and for such purpose is subjected.

These and other objects and advantages will be apparent to those skilled in the art from the following detailed description of our invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevation of the entire' machine;

FIG. 2 is a longitudinal vertical section through .the gathering head of the machine apart from the remainder of the machine, and with the path of drag conveyor being illustrated in dot-and-dashlines, the View being a section in the plane of line II-II of FIG. 4; f

FIG. 3 is a top plan View of the entire machine;V FIG. 4 is a horizontal section in substantially the plane of line IV--IV of FIG. 2; j j

FIG.` 5 is a View partly in vertical section and partly in elevation of one of they cutter arms;

FIG. 6 is a top planV View of the cutter arm shown in FIG. 5, but Vwith the foiward cutting assembly removed;

FIG. 7 is a vertical section through the drive for one of the cutter arms. v j

Referring rst to the overall organization of the machine and particularly FIGS. l and 3, it has a main inter- Y ing head is bottom plate structure 12 that normally supv `ports the gathering head on the mine floor, and which charge end of the machine.

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2 mediate chassis section A at the front of which is a gathering head B, and at the other end of the chassis is a rearwardly-extending adjustable conveyor discharge section C. There is a central longitudinally-extending drag chain conveyor to be hereinafter more fully described that reaches from the forward end of the gathering head to the dis- The machine is self-propelled, the chassis being mounted on independently-driven tractor-chains. The gathering head at the forward end has two horizontally oscillating gathering arms, one on each side of the center of the machine, that sweep over the mine floor and gather in the Coal which has been cut and push it into the path of an upwardly-sloping drag conveyor. Extending forwardly from each side of the machine over each gathering arm is a cutter arm that moves in a horizontal arc across the working face of the mine. The arm has a cutter head assembly at its outer end and a cutter chain rotates this assembly. The cutter head is vertically extensible to adapt itself to the height of the coal to be cut. These cutter arms cut anddig the coal loose and bring it into the path of the gathering arms which push it onto the conveyor. The endless conveyor moves the coal rearwardlyandout onto a boom that may swing up and down and sideways to discharge the coal into waiting mine cars or other conveying means. The operator crouches or lies along one side of the machine to operate the various controls.

The chassis A is comprised generally of two longitudinally-extending vertical side plates 2, supporting a forwardly and downwardly-extending conveyor plate or pan 3, and these side plates are connected by an under struc'- ture 4. The chassis is carried in a conventional manner on tractor bands or crawlers 5, one at each side of the chassis.

Thevmain` chassis carries the two electric motors that power the machine,these being at the rear end of the chassis section, one at each side of the conveyor, and they are designated 6A and 6B. The chassis, in addition to carrying the motors, also carries the fluid pressure pumps driven by the motors for driving hydraulic motors which operate the crawlers, the conveyor and the various hydraulic systems to be hereinafter described.

The gathering head The gathering head, which is best shown in FIGS. 2 and 4, without the attendant cutters,comprises a pair of vertical side plates 7 which are in line with the side plates 2 of the main chassis and a sloped conveyor pan 8 that forms a continuation of the pan 3 on the chassis section. At the forward end of the conveyor pan 8 is a transverse shaft 9 about which the drag conveyor passes at its forward end, this conveyor having a central chain 10 and transverse flights 11. For clarity of illustration it is only partly shown, or shown by dotted-lines in the several figures. Spaced below the conveyor pan 8 in the gatherat its rear end, has an upwardly sloping) portion 13 folded around a'transverse sleeve 14, providing a construction which will ride over irregularities when the machine is moved backwards. Between the pan 8, with its bracing structure 8a and the bottom plate is an enclosure or passage 15 through which the return reach of the conveyor moves to pass upwardly around thevshaft 9. Forwardly of the shaft 9 the gathering head has a pointed integral nose piece 16 which may shove under the coal to be loaded, and up which the coal will be pushed to be engaged by the conveyor. Coal which falls through opening 17 where the conveyor comes up around the shaft will be lifted out again by the conveyor working against 'plate 18 forming the rear `of the pointed nose.

As best shown in FIG. 4, the front endrof the gathering head flares outwardly to a width substantially greater than the width between the side plates '7, providing a wing-like housing at each side of the front portion, which housing has its bottom formed by an extension of the bottom plate 12, and which has side and rear walls 21, and there are vertical filler plates 22 and 23 in the two inner corners of each such enclosure. The front of the housing is open.

As best seen in FIG. 7, the top of this enclosure has a cover plate 24. The space between the cover plate 24 and the bottom plate is designated 25. There is a vertical pin 26 (see FIG. 7) that is inserted upward through the bottom plate, and which passes through the top plate, and which is removably held in place by a set screw 27. Around this pin is a hardened steel sleeve 26a, and the pin and sleeve provide a fulcrum for controlling the movement of a gathering arm, designated generally as 28.

Each gathering arm assembly 28 has a central portion 29 in which is a hole or crank pin socket 30 (see FIG. 4). Forwardly of the central portion the arm has two forwardly-opening divergent sockets 31 and 32. Secured in each of these sockets (see FIG. 7) is a rigid arm 33 on which is a paddle-like blade, the blade on one arm being designated 34a, and the one on the other arm is 341). The arm may be retained in the socket in any suitable way, as by a horizontal pin 35 (see FIG. 7) that allows limited vertical arcuate movement of the arm and its blade. The outer ends of the blades are curved toward the longitudinal center line of the machine.

Each gathering arm has a rearwardly-projecting extension 36 (see FIG. 4) offset inwardly toward the center line of the machine from the crank pin socket 30. This extension has an elongated straight slot 37 therein through which the guide or fulcrum pin 26 and sleeve 26a pass, and in which they have a working fit. This arm extension 36 extends back into the space 25.

The gathering head is attached to the front end of the chassis to pivot in a vertical arc so that it may be adjusted up and down relative to the chassis by a transverse shaft 14a passing through the sleeve 14 and through rearward extensions 38 (see FIG. 4) parallel with the side plates 7, and through openings in the forward ends of the side plates 2 of the chassis, the forward ends of the sides of the chassis fitting in the space 39 between the extensions 3S and the gathering head, so that the side plates 2 and 8 of the chassis and gathering head confront each other and lapping plates 39a, secured to the sides 7, cover the space between them (see FIG. 3). Hydraulic jacks 40 (see FIGS. l and 3) secured to the side plates 2 and to fixed brackets 41 at the back Wall of each wing are provided for vertically adjusting the gathering head relative to the chassis.

In FIG. 4, the dot-and-dash circle C indicates the path of movement of the crank pin; the kidney-shaped outlines P1 and 1:2 indicate the paths of movement of the paddle or scraper tips 34a and 34h respectively, and E indicates the path of movement described by the inner end of each extension 36 in the space 25. The drive for each arm comprises a crank pin engaged in bearings 46 in the socket 30 (see FIG. 7), which pin is at the outer end of a crank arm 47 on the bottom of a power-driven vertical shaft 48. The drive for these shafts will be hereinafter explained.

It will be noted in FIG. 4 and also in FIG. 2 that each side plate 7 has an opening therethrough, designated 49, that opens from the enclosed space 25 into the conveyor tunnel 15, so that any coal that enters the front of the space 24 is kicked or pushed by the arm extension 36 through the opening 24 into the under reach of the conveyor to be moved forwardly and then upwardly through Opening 17 to be conveyed away. The ller plates 22 and 23 aid in effecting this result. This arrangement prevents the coal from becoming impacted in the chamber 24 and is important to keeping space 25 free of such accumulation of coal as would interfere with the operation of the gathering arms.

In the operation of this part of the machine, the coal which is cut or broken down is gathered in by the arms which thrust forward from the position shown at the right of FIG. 4, sweep toward the center of the machine, and then swing in toward the nose, and then travel back diagonally in a slight arc to the starting position, the path of paddle or vane 34a overlapping that of paddle or vane 34h. The gathering arms thus have a wide reach over which they are effective to sweep coal laterally and rearwardly onto the nose of the gathering head. The position of the pins 26 with reference to the respective crank pins 45 determines the pattern of movement of these arms.

The cutter bars As most clearly shown in FIGS. 3 and 7, there is a heavy hollow casting at each side of the gathering head above the cover plate 24, and designated generally as 50. Since the cutter arms on each side of the machine are identical, the description of one applies equally to the other. This casting has a forwardly-extending ring portion 51, with a bottom 52. This bottom has an opening through which the shaft 48 projects, and the crank pin 45 is below this bottom. A cone bearing 53 in this opening is provided for the lower end of the shaft. There is bolted to the top of this ring-like housing a cover plate 54 with a central upwardly-extending hub portion 55 through which the upper end of the shaft 48 extends, there being a bearing assembly 56 in this hub for the upper portion of the shaft 48.

There is a horizontally-extending heavy plate 57 having an end part 58 (see FIG. 5) that encircles the hub 55, with a bearing ring 59 interposed between the hub and the encircling portion 88 of the plate 57. There is also a bearing plate 6i) `on the top of cover 54 on which the inner end 58 of the plate 57 rests. This plate is the inner end of the cutter arm or bar assembly, and by reason of this mounting, that assembly can swing in a horizontal arc about the axis of the `shaft 48 as a vertical center. The plate 57 has a bracket 61 secured to the under surface of plate 57 having a rabbetted end fitting over a flange 62 welded t-o the exterior of the ring portion 51, while a plate 63 bolted to this bracket fits under this flange to restrain the arm against upward movement and also further support the arm and permit itto swing.

The interior of the ring portion 51 constitutes a gear housing in which is a bevel gear 6-5 keyed to the vertical `shaft 48 through which this shaft is driven. This gear in turn is driven by a pinion 66 on a horizontal shaft 67 within the casting 50. Shaft 67 has a gear 68 at its rear end (left end as viewed in FIG. 7) which meshes with a driving gear 69 yon a drive shaft 70 that includes a universal joint 71. This shaft 70 has a second universal joint 72 at its rear end through which it is connected to a drive shaft projecting from gear box 73 at the front of the motor 6A in one case, and 6B in the other (see FIG. 3). Various bearings, oil rings and greasing connections are provided in accordance with sound engineering practice, but need not be described in detail.

The top of the shaft 48 is splined, and a cutter chain driving sprocket 74 is non-rotatably fitted thereto while a disk 75 is bolted to the top of the shaft and restrains the sprocket wheel against moving upwardly off the shaft.

In FIGS. 5 and 6 the heavy plate 57 extends under a longitudinally-adjustable forward section or casting 76 and the two are connected by bolts 77 passing through plate 57 and through slots 60 in the overlying section 76. An adjusting bolt 7711 screwed into the inner end of member 76, and having its head end bearing against an abutment 78 on the plate 57, provides for adjusting section 76 relative to section 57 lwhen the nuts on bolts 77 are loosened.

At its forward end ofthe casting 76 has a downwardlyoffset integral supporting sleeve 80 for the forward cutter assembly. Inside this sleeve 80 near the top and bottom Vthereof are cone-bearing assemblies 81 and 82 respectively,

for a rotatable Isleeve 83 concentric within sleeve 80. Be-

tween the upper and lower bearings 81 and 82 is a iluid transfer sleeve 84 to Iwhich hydraulic operating iluid under pressure is supplied through a hose nipple 85. |It has an annular channel 86 on its inner face, which channel registers with a port 87 opening into a vertical duct 88 in the rotatable sleeve 83. Since the port 87 -opens into the channel 86, -uid under pressure may thus be supplied to the sleeve as it rotates. Packings 89 above and below channel 86 confine the uid against leakage around the sleeve. A port 90 opens from the vertical duct 88 into the lower end lof the sleeve 83. A removable bottom plate 91 bolted to the bottom of the sleeve closes its lower end.

The interior wall of the rotatable sleeve 8f3 is vertically splined `and a shaft 92 with mating vsplines is telescoped into the sleeve 83. There is a piston 93 at the lower end of the shaft. The rotatable sleeve 83 extends .above the top lof the fixed supporting sleeve S0. A cutter chain sprocket 94 is keyed tothe top of the sleeve 83. The top of the shaft 92 extends above this sprocket wheel 94, and has a cutter wheel 95 secured thereto which is spaced above the -spr-ocket 94. The cutter wheel 95 has projecting sockets 96 on its periphery in which are removable cutter bits 97 projecting therefrom. These sockets may be vertically staggered and lthe bits set at different angles. The cutter bits are of the usual type used in mining -machinery, and are held in place by set screws (not shown) `on the sockets in avmanner well known in the art.

The lower end of the rotatable sleeve 83 extends bel-ow the -xed supporting `sleeve 80. On this lower end of the rotatable sleeve is keyed the-hub y1011 of the cutter drum, which is an integral casting having the hub y101, :a web 102, an upwardly-extending drum 103 that extends up around the :fixed sleeve 80 in spaced relation thereto. The cutter drum also has a downwardly and -outwardly-curved skirt 104. The skirt 104 is of a ydiameter :approximately the same as the diameter of the cutter wheel 95`at the top of the assembly, and it is provided .around its periphery with sockets 105 for -cut-ter bits 166, the same as the cutter wheel. The drum 103 has a ilange 107 of approximately the same diameter as the cutter wheel 95, and this flange also has an annular series -of spaced sockets 108 about its periphery with cutters 1.99 therein, as previously described. In addition, the drum has sockets k110 for breaker bits i111 above the cutters I109, but closer t-o the center of the drum, Iand similar sockets 112 for breaker bits 116 between the bits on the skirt and the bits lon the ange 107, but closer to the center.

The cutter assembly is driven by a cutter chain 114 that passes around sprocket 74 on shaft 43 and around sprocket wheel y94 on the rotatable sleeve I83. This cutter chain is of usual link construction with sockets 11'5 at intervals for removable cutter bits 116. The teeth 116 at the forward end of the machine move about the sprocket 94 in a curved path, the lcurvature of which is about the same radius as the cutter bits -on the periphery of the cutter wheel 95. t

The cutter wheel 95, the cutter chain, the flange 107, and the skirt 104 provide four vertically-spaced series of cutters to cut horizontal kerfs into the face of the coal, and between each two series there is a series of bre-aking cutters for breaking out the coal between the kerfs. The `skirt moves close to the mine ioor and, its cutters cu-t into the coal at the bottom of the seam, while the cutter wheel 95 works adjacent the roof. By .admitting or releasing iluid under pressure through -nipple,85, such pressure may be applied to the piston 93 at the lower end of shaft 92 that the cutter wheel 95 m-ay be raised or lowered to the height of the seam in which the machine is operating.

'I'he cutter assembly at the forward end of each cutter arm, being vertically extensible yover a range of several inches, contributes importantly to the utility ofthe machine. The multiple tiers of cutters, including the ones at the very top and the ones at the oor, enable coal to be removed across the full height of the coal. The

breaker bits intermediate the tiers of cutters provide an Vaction wherein after the cutter bits penetrate the coal, cutting parallel horizonal kerfs with intervening horizontal ribs of coal, are then contacted by the breaker bits and broken out in chunks. This results in a large percentage of the coal being removed as lump coal, which is desirable.

As shown in FIG. 3, the cutting is effected by oscillating the cutter arms horizontally to move the cutter heads or assemblies across the face of the coal. Starting with the two arms spread apart, they are swung inwardly toward each other, cutting and breaking out the c-oal as they move, and since the cutter bits travel toward the longitudinal center line of the machine as indicated by vthe arrows in FIG. 3, the coal is thrown inwardly and moved to the rear where it is caught in the sweep of the gathering arms and moved up onto the nose at the forward end of the machine to be carried to the rear by the` conveyor. When a cut has been completed, the cutter arms are again spread apart and the machine advanced to make the next cut. The cutter arms, moving in from opposite sides, create forces at opposite sides of the longitudinal center of the machine, tending to balance each other.

For moving the cutter arms horizontally, each arm has a bracket 117 (see FIG. 6)` attached to the inner face of the inner plate section 57. To this bracket is pivotally attached one end of a pistonrod 118 of a hydraulic jack v119 (see FIG. 3), the rear end of theV cylinder of which is pivotally attached to a bracket 120, forming part of bracket 41, on the side plate 2 of the chassis, the pivotal connection being vertical. When the jack is operated from the full line position of FIG. 3, the piston rod is pulled rearwardly, and since the bracket is eccentric to the pivotal axis of the cutter arm, the arm is caused to swing toward the longitudinal center line of the machine. The two jacks 119 have a limited stroke and limited arc Vof swing so that while the cutter heads of the two arms can be brought into close proximity, as indicated in FIG. 3, they cannot actually contact each other as theyconverge, but they are so close that the wedge of coal on the working face between the two cutter heads which will not be cut, will easily break out of the succeeding cut.

The discharge end of tlhe machine The gathering end and cutter bars and cutter heads terminal conveyor section 128 which may be of the gen-v eral construction shown for example in Arentzen P-atent No. 2,766,871, granted October 16, 1956, being movable about a vertical pivot point indicated in FIG. 3 at 129. Hydraulic jacks 130 acting through cables 131 elfect the horizontal movement of the terminal section. The conveyor chain passes around a terminal shaft 132 (FIG. l) which may be automatically adjusted as described for example in the Arentzen patent or in any other manner known to the art to accommodate for the change in length required as the conveyor swings toward or away from a central position.

The conveyor may be driven in any suitable manner. There is here shown in FIG. 1 a transverse shaft 135 which may be driven by a hydraulic motor. The conveyor chain passes over a roller 137 and is then looped around sprockets -on the shaft 135. It passes up over an idler roller 138 that is horizontally slidable in the side plates 2. This idler is arranged to be moved by a hydraulic jack 139 for keeping the conveyor chain under tension.

At each side of the chassis near the forward end is a double-acting vertical hydraulic jack 144 having a foot 144e that may be extended upon operation of the jack. This is very useful in case the operator must make repairs to the crawlers or to the gathering arms, or for other purposes.

The machine as thus constructed will operate in seams from twenty-eight to forty inches in height, and can be maneuvered and operated within close confines. Each sweep of the cutter arms will remove coal over a face much wider than the width of the machine and over the full height of the machine. By having the cutter arms pivoted between their ends so as to permit adjustment of the cutter heads up and down, the cutting operation can follow closely the irregularities in the floor. These and other advantages will be apparent to those skilled in the art.

While we have shown and described one preferred ernbodiment of `our invention, -it will be understood that this is by way of illustration and that various modifications and changes may be made in the construction and arrangement of parts within the contemplation of our invention.

We claim:

1. A mining machine cutter arm comprising a vertical shaft, a rigid arm mounted at its inner end for movement in a horizontal arc about said shaft as an axis, means for driving the shaft, a cutter head assembly at the outer end of the arm rotatable about a vertical axis, sprocket wheels on the said shaft and the cutter head assembly, a cutter chain passing around said sprockets for driving the cutter head assembly from the shaft, a plurality of cutter Wheels on the rotatable cutter head assembly spaced vertically from each other and from the chain, and breaker bits on the cutter head assembly between the cutter wheels and between the cutter wheels and the chain sprocket, the breaker hits extending a less distance from the axis of rotation of the cutter head assembly than the cutter wheels, the aforesaid vertical shaft having a crank on its lower end, a gathering arm below the cutter arm, the crank being engaged with the gathering arm for oscillating said gathering arm in a path below the cutter arm and said shaft of the cutter assembly such as to sweep material from the area at the back of the cutter head toward the rear end of said rigid arm.

Z. A mining machine comprising a mobile chassis, a gathering head at the forward end of the chassis having a downwardly and forwardly-sloping gathering apron, a centrally-located conveyor extending longitudinally of the chassis from the apron to the rearend of the machine for moving material from the apron to the rear of the machine, a cutter arm at each side of the gathering head having an inner end and an outer end, a drive shaft at the inner end of each arm comprising also a pivot for attaching the inner end of each arm to the side of the gathering head on which it is located whereby each arm may swing in a horizontal arc at the forward end of the machine toward and away from the longitudinal axis of the machine, each arm being independent of the other, a sprocket wheel on the top of each of said shafts, a crank with a downwardly-projecting crank pin on the lower end of each of said shafts, means on the machine for rotating each of said shafts, a cutter head on the outer end of each cutter arm rotatable about a vertical axis, a sprocket wheel on the upper portion of said cutter head, a sprocket chain engaging the sprocket wheel on the pivot-forming shaft for each arm and the sprocket wheel of the cutter head at the outer end of the corresponding cutter arm, a gathering arm near oor level at each side of the gathering head under the respective cutter arms below each crank movable horizontally in a transversely-elongated ovate path under each cutter arm between the apron 9 o and the cutter at the forward end `of the arm under which it is located, the crank pin on each of said shafts engaging one of the gathering arms for moving it when the shaft is rotated, and cooperating means on the machine and gathering arm for causing the gathering arm to travel upon rotation of the crank in such transversely-elongated ovate path.

3. A mining machine comprising a chassis having a downwardly and forwardly-sloping gathering section at its forward end, said chassis and gathering section having an axially-extending conveyor pan, a drag chain conveyor movable longitudinally -of the machine in a return path under the conveyor pan, upwardly at the forward end of the gathering sections and rearwardly over the top of the conveyor pan, a pair of cutter arms, one of which is secured to the gathering head at each side of the conveyor pan and extending forwardly beyond the end Iof the gathering section, each cutter arm comprising a frame supported at its inner end on a side of the gathering head for movement of its outer end in a horizontal arc toward and away from the longitudinal axis of the machine and toward and away from the other such arm, a cutter head at the outer end of each arm mounted for rotation about a vertical axis and having a plurality of horizontal tiers of cutters thereabout, a gathering arm located under each cutter arm, each gathering arm having a forwardlyextending portion positioned between the inner end of the cutter arm and the cutter head at the outer end of each of the cutter arms, means for imparting a compound oscillating and rectilinear motion to each gathering arm in a path to sweep outwardly and forwardly and then inwardly and rearwardly and thereby remove material from behind the cutter head onto the conveyor gathering pan, said means for operating the gathering arm comprising a shaft defining the axis about which the cutter arm pivots, means for driving the shaft, said means for imparting movement to the gathering means comprising a crank on the lower end of said shaft above the gathering arm, the crank having a crank pin engaging the gathering arm intermediate its ends, the gathering arm having a guiding extension extending rearwardly from the crank pin, a housing at the side of the gathering section into which said extension projects, and means in the housing engaging the guiding extension of the gathering arm and relative to which the guiding extension has limited pivotal and rectilinear travel for defining the movement of the gathering arm when the crank is rotated to combine the oscillating and rectilinear movement -of the arm.

References Cited hy the Examiner UNITED STATES PATENTS 1,500,352 7/24 Walker. 1,945,340 1/34 Arentzen 198-10 2,283,212 5/42 Joy. 2,643,106 6/53 McGowan. 2,684,234 7/54 West 198-10 2,695,164 11/56 Arentzen. 2,770,448 11/ 56 Miller. 2,808,253 10/57 Miller. 2,916,274 12/ 5 9 Haworth et al. 2,933,294 4/ 60 Meehan.

FOREIGN PATENTS 549,842 8/56 Belgium. 1,159,933 2/58 France.

939,441 2/56 Germany.

941,841 4/56 Germany.

800,894 9/58 Great Britain.

BENIAMIN HERSH, Primary Examiner. WILLIAM I. KANOF, PHILIP ARNOLD, Examiners. 

1. A MINING MACHINE CUTTER ARM COMPRISING A VERTICAL SHAFT, A RIGID ARM MOUNTED AT ITS INNER END FOR MOVEMENT IN A HORIZONTAL ARC ABOUT SAID SHAFT AS AN AXIS, MEANS FOR DRIVING THE SHAFT, A CUTTER HEAD ASSEMBLY AT THE OUTER END OF THE ARM ROTATABLE ABOUT A VERTICAL AXIS, SPROCKET WHEELS ON THE SAID SHAFT AND THE CUTTER HEAD ASSEMBLY, A CUTTER CHAIN PASSING AROUND SAID SPROCKETS FOR DRIVING THE CUTTER HEAD ASSEMBLY FROM THE SHAFT, A PLURALITY OF CUTTER WHEELS ON THE ROTATABLE CUTTER HEAD ASSEMBLY SPACED VERTICALLY FROM EACH OTHER AND FROM THE CHAIN, AND BREAKER BITS ON THE CUTTER HEAD ASSEMBLY BETWEEN THE CUTTER WHEELS AND BETWEEN THE CUTTER WHEELS AND THE CHAIN SPROCKET, THE BREAKER BITS EXTENDING A LESS DISTANCE FROM THE AXIS OF ROTATION OF THE CUTTER HEAD ASSEMBLY THAN THE CUTTER WHEELS, THE AFORESAID VERTICAL SHAFT HAVING A CRANK ON ITS LOWER END, A GATHERING ARM BELOW THE CUTTER ARM, THE CRANK BEING ENGAGED WITH THE GATHERING ARM FOR OSCILLATING SAID GATHERING ARM IN A PATH BELOW THE CUTTER ARM AND SAID SHAFT OF THE CUTTER ASSEMBLY SUCH AS TO SWEEP MATERIAL FROM THE AREA AT THE BACK OF THE CUTTER HEAD TOWARD THE REAR END OF SAID RIGID ARM. 